Project Summary/Abstract: Over the past 100+ years, studies in Drosophila melanogaster (Drosophila or flies) have contributed enormously to our understanding of the genetic basis for sex-determination, development, behavior, aging, disease and many other normal as well as pathophysiological processes. More recently, the fly model has also been used to explore the contribution of environmental factors in health and disease. Key among the environmental factors being investigated is diet. Altering the diet of flies has profound effects on their physiology, progression of disease markers and aging. For example, dietary restriction in flies (via reduced concentrations of nutrients) extends lifespan as found in other species. Changes in the fly diet also greatly impact egg-laying (an indicator of resource utilization) and can lead to the development of a type II diabetes-like state. Furthermore, our preliminary studies indicate that diet has a pronounced effect on ethanol sedation behavior in flies. Given the effects of diet in flies, the ongoing global obesity epidemic and the increasing incidence of obesity-related diseases, studies in flies hold tremendous promise for continuing to uncover key mechanisms underlying diet-related phenomena that could ultimately translate into improved prevention and treatment of a multitude of diet-related diseases in humans. We have consequently begun developing dye-based methods (Con-Ex) for measuring food consumption in flies. The overarching goals of the studies in this application are to (i) use our previously established dye-based Con-Ex feeding method with the dye Blue-1 as a food tracer to assess intake of diets that alter longevity?and importantly do so across the lifespans of flies and (ii) extend the utility of the method by identifying and validating dyes in addition to Blue-1 for use in Con-Ex studies. The proposed studies will address an important question related to the effects of diet on longevity and will lay the foundation for more sophisticated dietary consumption analyses in flies.